What's the difference between EUI-48 and MAC-48?

Historically, both EUI-48 and MAC-48 were concatenations of a 24-bit OUI (Organizationally Unique Identifier)
assigned by the IEEE and a 24-bit extension identifier assigned by the organization with that OUI assignment
(NIC).

The distinction between EUI-48 and MAC-48 identifiers is merely nominal: MAC-48 is used for network hardware;
EUI-48 is used to identify other devices and software. (Thus, by definition, an EUI-48 is not in fact a "MAC
address", although it is syntactically indistinguishable from one and assigned from the same numbering
space.)

The IEEE now considers the label MAC-48 to be an obsolete term formerly used to refer to a specific type of
EUI-48 identifier that addresses hardware interfaces within existing 802-based networking applications.
Therefore, it is unlikely to be used in the future. Instead, the proprietary term EUI-48 should serve this
purpose.

The EUI-48 is expected to have exhausted its address space by the year 2100.

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